Boron tribromide → 2,3-Difluoro-4-methyl-5-nitro-phenol

HRID 2065745Notes

Reaction equation

HRID 2065745 reaction equation
COC(=O)[O:4][C:5]1[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[C:8]([CH3:14])=[C:7]([F:15])[C:6]=1[F:16].B(Br)(Br)Br>ClCCl>[F:16][C:6]1[C:7]([F:15])=[C:8]([CH3:14])[C:9]([N+:11]([O-:13])=[O:12])=[CH:10][C:5]=1[OH:4]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 59377938Carbonic acid 2,3-difluoro-4-methyl-5-nitro-phenyl ester methyl ester

Product 1

HCID 593779072,3-Difluoro-4-methyl-5-nitro-phenolYield 58%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of carbonic acid 2,3-difluoro-4-methyl-5-nitro-phenyl ester methyl ester (2.3 g, 9.3 mmol) in dichloromethane (30 ml) was cooled to 0° C. in an ice bath, and 1.0M boron tribromide in dichloromethane (9.3 ml, 9.3 mmol) was added. The ice-bath was removed and the mixture was stirred at room temperature for 18 hours. Water was added and the mixture was extracted with EtOAc. The combined extracts were washed with water and brine, dried over MgSO4, filtered and concentrated to dryness under reduced pressure. Purification of the crude product by flash chromatography (hexanes:EtOAc 9:1) gave 1.02 g (58%) of 2,3-difluoro-4-methyl-5-nitro-phenol as a white solid.

Workup

  1. customThe ice-bath was removed
  2. additionWater was added
  3. extractionthe mixture was extracted with EtOAc
  4. washThe combined extracts were washed with water and brine
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated to dryness under reduced pressure
  8. customPurification of the crude product by flash chromatography (hexanes:EtOAc 9:1)

Sources & evidence

ORD record
ord-1ff7a241f398436b863a577cfe1db708
Source dataset
uspto-grants-2012_10
Patent number
US08288552B2

Reaction notes

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